Elucidating the biological basis of perception and cognition has been an enduring goal of neuroscience research because it is essential for treating brain disorders that can devastate the ability to think and act. Higher mental processes have traditionally been attributed to the prefrontal cortex, the part of the brain most developed in higher primates and humans. In recent years, however, it has become clear that many neural correlates of mental functions are not exclusive traits of the prefrontal cortex but are already evident in the cortical pathways that project to it, for example, the association areas of the temporal and parietal lobes. Uncovering the unique and cooperative roles of these cortical regions is therefore necessary for understanding the biological basis of higher mental functions. Even less is known about how the circuit organization and nature of neural processing differs between high-order cortical areas, so as to account for their distinct functional roles. We propose to use an integrative methodological framework to elucidate the unique and cooperative roles of areas involved with the processing of visual-spatial information. We will comparatively investigate the physiological responses and neural-circuit organization of the dorsal prefrontal and posterior parietal cortex. Our experiments will make use of neurophysiological recordings with arrays of closely-spaced electrodes in monkeys trained to perform visual-spatial tasks. We will examine the patterns of neural responses during the presentation of multiple visual stimuli, concurrently or in sequence, and analyze the functional interactions between neurons. Experiments will specifically test whether prefrontal cortex is characterized by more robust, more widely distributed or dynamically modulated neuronal connectivity, or functionally specialized cell types. These experiments will help unveil the functional specialization of cortical areas involved in higher cognitive functions and offer insights on normal perceptual processing as well as the consequences of brain injury and mental illness. PUBLIC HEALTH RELEVANCE Understanding the organization and function of cortical areas mediating higher cognitive processes is key to ameliorating the disorders that can devastate one's ability to think and act. The proposed research will rely on a primate model to determine the role and functional specialization of two areas of the cerebral cortex involved in the processing of visual spatial information, the posterior parietal and dorsal prefrontal cortex.